The present invention relates to diodes, and more specifically, to gate tunable diodes via an electric field.
Diodes are constructed from the same type of silicon as transistors, but they are simpler devices that have only two terminals. Called the anode and cathode, the two ends of the diode are constructed of positively doped silicon (the anode) joined directly to negatively doped silicon (the cathode). This p-n junction exhibits the unique characteristic of allowing current to flow in only one direction (from the anode to the cathode). Diodes have a minimum threshold voltage (Vth or Vt), usually around 0.7 V (volts)) that must be present between the anode and cathode in order for current to flow. If the anode voltage is not at least Vt greater than the cathode voltage, no current will flow. Likewise, if the cathode voltage is greater than the anode voltage, the diode is said to be reverse-biased and no current will flow. In an ideal diode, if the diode voltage equals the threshold voltage (plus a small amount), then unlimited current can flow without causing the voltage across the diode to increase. If the diode is reversed-biased, no current will flow regardless of the reverse-voltage magnitude.